Article Text

Download PDFPDF

Association between perinatal interventional activity and 2-year outcome of Swiss extremely preterm born infants: a population-based cohort study
  1. Mark Adams1,2,
  2. Thomas M Berger3,
  3. Cristina Borradori-Tolsa4,
  4. Myriam Bickle-Graz5,
  5. Sebastian Grunt6,
  6. Roland Gerull7,
  7. Dirk Bassler1,
  8. Giancarlo Natalucci1
  9. For the Swiss Neonatal Network & Follow-Up Group
    1. 1 Department of Neonatology, Universitätsspital Zürich, Zürich, Switzerland
    2. 2 Epidemiology, Biostatistics and Prevention Institute, University Zürich, Zürich, Schweiz, Switzerland
    3. 3 Neonatal and Paediatric Intensive Care Unit, Kinderspital Luzern, Luzern, Switzerland
    4. 4 Department of Paediatrics, Geneva University Hospital, Geneva, Switzerland
    5. 5 Department Woman-Mother-Child, University Hospital Lausanne, Lausanne, Switzerland
    6. 6 Division of Neuropaediatrics, Development and Rehabilitation, Children’s University Hospital, Inselspital, University of Bern, Bern, Switzerland
    7. 7 Department of Neonatology, University of Basel Children’s Hospital (UKBB), Basel, Switzerland
    1. Correspondence to Dr Mark Adams; mark.adams{at}


    Objectives To investigate if centre-specific levels of perinatal interventional activity were associated with neonatal and neurodevelopmental outcome at 2 years of age in two separately analysed cohorts of infants: cohort A born at 22–25 and cohort B born at 26–27 gestational weeks, respectively.

    Design Geographically defined, retrospective cohort study.

    Setting All nine level III perinatal centres (neonatal intensive care units and affiliated obstetrical services) in Switzerland.

    Patients All live-born infants in Switzerland in 2006–2013 below 28 gestational weeks, excluding infants with major congenital malformation.

    Outcome measures Outcomes at 2 years corrected for prematurity were mortality, survival with any major neonatal morbidity and with severe-to-moderate neurodevelopmental impairment (NDI).

    Results Cohort A associated birth in a centre with high perinatal activity with low mortality adjusted OR (aOR 0.22; 95% CI 0.16 to 0.32), while no association was observed with survival with major morbidity (aOR 0.74; 95% CI 0.46 to 1.19) and with NDI (aOR 0.97; 95% CI 0.46 to 2.02). Median age at death (8 vs 4 days) and length of stay (100 vs 73 days) were higher in high than in low activity centres. The results for cohort B mirrored those for cohort A.

    Conclusions Centres with high perinatal activity in Switzerland have a significantly lower risk for mortality while having comparable outcomes among survivors. This confirms the results of other studies but in a geographically defined area applying a more restrictive approach to initiation of perinatal intensive care than previous studies. The study adds that infants up to 28 weeks benefited from a higher perinatal activity and why further research is required to better estimate the added burden on children who ultimately do not survive.

    • neonatology
    • fetal medicine
    • quality in health care

    This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


    • Contributors MA performed the biostatistical evaluation and together with GN was involved in study design, data collection, analysis and interpretation of the results and wrote, reviewed and revised the manuscript. TMB, DB, CB-T, MB-G, SG and RG were involved in data collection, study design, analysis and interpretation of data and reviewed the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

    • Funding MA receives a salary as network coordinator for the Swiss Neonatal Network. GN received financial support by the Swiss National Science Foundation; grant PZOOP3_161146.

    • Disclaimer The authors received no specific funding for this work. The sponsors were not involved in the following matters: study design; collection, analysis, and interpretation of data; writing of the report and the decision to submit the manuscript for publication.

    • Competing interests MA receives a salary as network coordinator for the Swiss Neonatal Network.

    • Ethics approval Data collection and evaluation for this study has been approved by the institutional ethical review board (KEK-ZH-Nr 2014–0552).

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Data sharing statement Additional data are available by emailing

    • Collaborators Swiss Neonatal Network & Follow-up Group: Aarau: Cantonal Hospital Aarau, Children’s Clinic, Department of Neonatology (Ph. Meyer, C. Anderegg), Department of Neuropaediatrics (A. Capone Mori, D. Kaeppeli); Basel: University of Basel Children’s Hospital (UKBB), Department of Neonatology (S. Schulzke), Department of Neuropaediatrics and Developmental Medicine (P. Weber); Bellinzona: San Giovanni Hospital, Department of Paediatrics (G.P. Ramelli, B. Goeggel Simonetti); Berne: University Hospital Berne, Department of Neonatology (M. Nelle), Department of Paediatrics (B. Wagner), Department of Neuropaediatrics (M. Steinlin, S. Grunt); Biel: Children’s Hospital Wildermeth, Department of Pediatrics (M. Gebauer), Development and Paediatric Neurorehabilitation Center (R. Hassink); Chur: Children’s Hospital Chur, Department of Neonatology (W. Bär), Department of Neuropaediatrics (E. Keller, Ch. Killer); Fribourg: Cantonal Hospital Fribourg, Department of Neuropaediatrics (K. Fuhrer); Geneva: Department of child and adolescent, University Hospital (HUG), Neonatology Units (R. E. Pfister), Division of Development and Growth (P. S. Hüppi, C. Borradori-Tolsa); Lausanne: University Hospital (CHUV), Department of Neonatology (J.-F. Tolsa, M. Roth-Kleiner), Department of Child Development (M. Bickle-Graz); Lucerne: Children’s Hospital of Lucerne, Neonatal and Paediatric Intensive Care Unit (T. M. Berger), Department of Neuropaediatrics (T. Schmitt-Mechelke, F. Bauder); Lugano: Regional Hospital Lugano, Department of Paediatrics (V. Pezzoli); Muensterlingen: Cantonal Hospital Muensterlingen, Department of Paediatrics (B. Erkert, A. Mueller); Neuchatel: Cantonal Hospital Neuchatel, Department of Paediatrics (M. Ecoffey); St. Gallen: Cantonal Hospital St. Gallen, Department of Neonatology (A. Malzacher), Children’s Hospital St. Gallen, Neonatal and Paediatric Intensive Care Unit (J. P. Micallef), Department of Child Development (A. Lang-Dullenkopf); Winterthur: Cantonal Hospital Winterthur, Department of Neonatology (L. Hegi), Social Paediatrics Center (M. von Rhein); Zurich: University Hospital Zurich (USZ), Department of Neonatology (D. Bassler, R. Arlettaz), University Children’s Hospital Zurich, Department of Neonatology (V. Bernet) and Child Development Center (B. Latal, G. Natalucci); Zollikerberg: Hospital Zollikerberg, Neonatology Clinic (M. Moenkhoff).

    • Patient consent for publication Not required.